Transfer film, process for producing a transfer film and process for recycling a transfer film

Abstract

A process for recycling a transfer film (1) and a transfer film (1) suitable for this having a carrier film (2) and a transfer ply (4) arranged at least partially on the carrier film (2), wherein a detachment layer (3) is arranged between the carrier film (2) and the transfer ply (4), and wherein the transfer ply (4) has an alkali-soluble topcoat (5), wherein the topcoat (5) is arranged on the detachment layer (3), and wherein the following step is carried out in the process:x) dissolving (10) the alkali-soluble topcoat (5), in particular the alkali-soluble binder of the topcoat (5), by means of an alkaline washing liquid (9), preferably in a washing liquid bath, wherein the transfer ply (4) is detached from the carrier film (2).

1 . A transfer film having a carrier film and a transfer ply arranged at least partially on the carrier film, wherein a detachment layer is arranged between the carrier film and the transfer ply, and
 wherein the transfer ply has an alkali-soluble topcoat, wherein the topcoat is arranged on the detachment layer.   
     
     
         2 . The transfer film according to  claim 1 , wherein at least 40% to 100% of the topcoat comprises a binder or binder mixture, which is at least 50% soluble in an alkaline washing liquid with a pH greater than 8.5. 
     
     
         3 . The transfer film according to  claim 1 , wherein the topcoat is transparent, semitransparent, transparent dyed, dyed, opaque and/or matte. 
     
     
         4 . The transfer film according to  claim 1 , wherein the topcoat has a layer thickness of the dried layer in the range of from 0.2 μm to 20.0 μm. 
     
     
         5 . The transfer film according to  claim 1 , wherein the detachment layer has an application weight of the dried layer in the range of from 0.001 μm to 0.080 μm. 
     
     
         6 . The transfer film according to  claim 1 , wherein the detachment layer is formed transparent and/or translucent and/or opaque and/or dyed and/or at least partially dyed and/or crystal clear. 
     
     
         7 . The transfer film according to  claim 1 , wherein the transfer ply has further layers selected individually or in combination from: at least one metal layer, at least one primer layer, at least one color layer, at least one adhesive layer, at least one adhesion-promoter layer, at least one barrier layer, at least one protective layer, at least one replication layer, at least one oxide layer, at least one mask layer. 
     
     
         8 . The transfer film according to  claim 7 , wherein the transfer ply has a primer layer having a layer thickness of the dried layer in the range of from 0.1 μm to 5.0 μm. 
     
     
         9 . The transfer film according to  claim 7 , wherein the transfer ply has an adhesion-promoter layer having a layer thickness in a range of from 0.01 μm to 0.5 μm. 
     
     
         10 . The transfer film according to  claim 1 , wherein the carrier film has a layer thickness in the range of from 4.5 μm to 100 μm. 
     
     
         11 . The transfer film according to  claim 1 , wherein the carrier film comprises a main constituent, wherein the proportion of the main constituent in the carrier film is more than 97%. 
     
     
         12 . The transfer film according to  claim 1 , wherein the carrier film is colorless, transparent, crystal clear, opaque, dyed, at least partially dyed or colored. 
     
     
         13 . The transfer film according to  claim 1 , wherein the detachment force for detaching the transfer ply from the carrier film lies in a range of from 1 cN/cm to 10 cN/cm. 
     
     
         14 . The transfer film according to  claim 1 , wherein the smallest detachment force within or between two or more layers of the transfer ply is at least twice as large as the force for detaching the transfer ply from the carrier film. 
     
     
         15 . A process for producing a transfer film, wherein the following steps are carried out:
 providing a carrier film;   applying a detachment layer to the carrier film; and   applying one or more layers of a transfer ply, wherein an alkali-soluble topcoat is applied as first layer of the transfer ply such that the topcoat is arranged on the detachment layer.   
     
     
         16 . The process for producing a transfer film according to  claim 15 , wherein the topcoat is applied with an application weight of the dried layer in the range of from 0.5 g/m 2  to 20.0 g/m 2 . 
     
     
         17 . The process for producing a transfer film according to  claim 15 , wherein the topcoat is applied in the aqueous state and is then dried, wherein alkaline additives are completely or at least partially removed by drying. 
     
     
         18 . The process for producing a transfer film according to  claim 15 , wherein the aqueous topcoat has a solids content in the range of from 5% to 45%. 
     
     
         19 . The process for producing a transfer film according to  claim 15 , wherein the detachment layer is applied by means of a gravure printing process with an application weight of the dried layer in the range of from 0.001 g/m 2  to 0.060 g/m 2 . 
     
     
         20 . The process according to  claim 15 , wherein a primer layer is applied as one of the one or more layers of the transfer ply by means of a printing process and/or by means of pouring and/or by means of doctor blade. 
     
     
         21 . The process according to  claim 20 , wherein the primer layer is applied with an application weight of the dried layer in the range of from 0.2 g/m 2  to 5.0 g/m 2 . 
     
     
         22 . A process for recycling a transfer film having a carrier film and a transfer ply arranged at least partially on the carrier film, wherein a detachment layer is arranged between the carrier film and the transfer ply, and wherein the transfer ply has an alkali-soluble topcoat, wherein the topcoat is arranged on the detachment layer, and wherein the following step is carried out in the process:
 x) dissolving the alkali-soluble topcoat by means of an alkaline washing liquid, wherein the transfer ply is detached from the carrier film.   
     
     
         23 . The process according to  claim 22 , wherein after step x), the carrier film and/or the material of the carrier film has a purity in the range of from 99.0 wt.-% to 100.0 wt.-%. 
     
     
         24 . The process according to  claim 22 , wherein during step x), the topcoat is dissolved in that the alkaline washing liquid soaks into the transfer film and/or between carrier film and transfer ply via cut edges and/or broken edges and/or cracks and/or microcracks of the transfer film. 
     
     
         25 . The process according to  claim 22 , wherein during step x) the transfer ply disintegrates into particles, wherein the particles are insoluble in the alkaline washing liquid. 
     
     
         26 . The process according to  claim 22 , wherein in step x), the alkaline washing liquid has a pH greater than 9. 
     
     
         27 . The process according to  claim 22 , wherein the alkaline washing liquid comprises one or more solutions of the following solutions: solutions of alkali metal or alkaline earth metal hydroxides, or alkaline earth oxides, or solutions of ammonia or amines. 
     
     
         28 . The process according to  claim 22 , wherein the alkaline washing liquid has a density in the range of from 1.2 g/cm 3  to 1.4 g/cm 3 . 
     
     
         29 . The process according to  claim 22 , wherein step x) is carried out at ambient temperature. 
     
     
         30 . The process according to  claim 22 , wherein the following step is carried out before step x) in the process:
 a) comminuting the transfer film by means of a cutting device into cut material.   
     
     
         31 . The process according to  claim 30 , wherein in step a), the cut material has in each case a surface area in the range of from 0.1 cm 2  to 100 cm 2 . 
     
     
         32 . The process according to  claim 30 , wherein the cut material in the alkaline washing liquid has a concentration in the range of from 1 wt.-% to 30 wt.-% during step x). 
     
     
         33 . The process according to  claim 30 , wherein the alkaline washing liquid is stirred with the transfer film and/or the cut material during step x). 
     
     
         34 . The process according to  claim 30 , wherein the alkaline washing liquid is stirred with the transfer film and/or the cut material during step x) with a stirring duration in a range of from 30 seconds to 120 seconds. 
     
     
         35 . The process according to  claim 30 , wherein the alkaline washing liquid is stirred with the transfer film and/or the cut material during step x) with a stirring speed of a stirrer in a range of from 1 to 200 revolutions. 
     
     
         36 . The process according to  claim 30 , wherein the transfer ply of the cut material detaches from the carrier film with the result that particles of the transfer ply and carrier film cuttings form during step x). 
     
     
         37 . The process according to  claim 36 , wherein the carrier film cuttings are separated from the alkaline washing liquid by means of filtration and/or centrifugation and/or sedimentation. 
     
     
         38 . The process according to  claim 36 , wherein the separated carrier film cuttings are washed and/or neutralized and/or dried. 
     
     
         39 . The process according to  claim 22 , wherein the process has the following step before step x):
 b1) unwinding the transfer film from a feed roll by means of an unwinding device, wherein the unwound transfer film is brought into contact with the alkaline washing liquid.   
     
     
         40 . The process according to  claim 39 , wherein the process has the following step after step b1) and after step x):
 b2) winding the carrier film onto a take-up roll, wherein the carrier film is guided out of the bath of the alkaline washing liquid.   
     
     
         41 . The process according to  claim 40 , wherein a mechanical abrasion system and/or a brush roll system and/or a foam roll system and/or a spray nozzle system is additionally used to detach the transfer ply from the carrier film in step x) and/or between steps b1) and b2). 
     
     
         42 . The process according to  claim 22 , wherein insoluble particles of the transfer ply are separated from the alkaline washing liquid by means of a separation process after step x). 
     
     
         43 . The process according to  claim 22 , wherein the alkaline washing liquid is reprocessed by means of membrane filtration and/or chemical precipitation after step x). 
     
     
         44 . The process according to  claim 22 , wherein the carrier film and/or the carrier film cuttings and/or the material of the carrier film are further processed into a compact product and/or extrusion product after step x).